Photorefractive materials and their applications in optical image processing

A brief review of a band transport model for the photorefractive effect is given. Distinction is made between the influence of intrinsic material dependent parameters and externally controlled parameters on the form of the optical nonlinearity. These considerations are made in the context of dynamic holographic optical processing applications. Examples of adaptive optical and Fourier-plane image processing using four-wave mixing in photorefractive bismuth silicon oxide crystals are discussed. Critical assessment is then made of the use of photorefractive materials in image cross-correlation schemes.